Ions

Week 6

100

H⁺

Hydrogen

200

Fe²⁺

Iron ll

300

Cr³⁺

Chromium lll

400

Hydride

H^-

500

Chromate

CrO₄^2-

Week 7

100

Sulfide

S^2-

200

Nitrite

NO₂^-

300

Lead ll

Pb²⁺

400

C₂O₄^2-

Oxalate

500

Sr²⁺

Strontium

Week 8

100

Ni²⁺

Nickel ll

200

Pb⁴⁺

Lead lV

300

Iodine

I^-

400

ClO^-

Perchlorate

500

Permanganate

MnO₄^-

Week 9

100

Sn²⁺

Tin ll

200

Be²⁺

Beryllium

300

Chlorite

ClO₂^-

400

Hydrogen Carbonate

HCO₃^-

500

O₂^2-

Peroxide

Week 10

100

Fe³⁺

Iron lll

200

Tin IV

Sn⁴⁺

300

ClO^-

Hydrochlorite

400

SO₃^2-

Sulfide

500

Dichromate

Cr₂O₇^2-